This invention is directed to a fuse element or detonator containing, in a cylindrical-symmetric arrangement and layered, in succession, an igniter charge, a delay section made up of one or several delay charges, and a detonative or flash yielding charge layer and a method of producing this element or detonator.
A fuse element with a delay section serves the purpose of enhancing the pyrotechnical reaction produced upon triggering of a detonator composition in such a way that this reaction, after a delay period, leads to the sure detonation or ignition of a primary charge, usually within the fuse element.
A fuse element is built up of several, series-arranged pyrotechnical charges: the highly sensitive but weak triggering of an igniter charge is to be utilized, after a predetermined period of time, for the sure ignition of a primary charge. The weak points of a fuse element where passage of the reaction zone can be disturbed or interrupted are the areas where pyrotechnical compositions having differing physical and chemical properties abut or contact one another. At such interfaces, the reaction process ceases, above all, if progression of the reaction is made difficult by other additional conditions, such as, for example, by a very high rotation of the fuse element, by low temperatures, by vibrations, impacts, shocks, and the like.
Also, the requirement of long delay periods normally is accompanied by a decrease in reliability, because the delay charges suitable for this purpose have such a chemical composition that the desired gradual transmission takes place with certainty only with optimum initiation of the reaction in the delay section.